This may be a stupid question but........Im trying to figure out how many gallons are in my friends pool that I'm helping her slam. I thought I could figure it out by how many gallons of chlorine I had added to get her to her slam level but math is not my strong point. So any help is appreciated.
She thinks the size is a 20x40 IG Grecian. Shallow end is 4' deep end is 8'. But she is not positive.
So I added:
4 gallons of chlorine 10%
Raised her FC to 13.
Is it possible to figure out the gallons this way?